Reactions of Thiyl Radicals. VIII. Photolysis of Methyl Ethyl Sulfide Vapor

Abstract

Methyl ethyl sulfide has been photolyzed in the vapor phase with wavelengths between 2000 and 2350 A and the effects of pressure, temperature, and exposure time investigated. The vapor phase absorption spectrum of the sulfide has been determined and the variation in the nature and rates of formation of products in the presence of C 0 2 , CF,, propylene, and 2-pentene measured. Quantum yields of products from the decomposition of the pure substrate were determined at 2288 A.The products of the reaction are, in order of decreasing importance, C2H6, CH3SSC2H,, C,H,SSC,H,, CH,, CH3SCH3, C2H,SC2H,, C3Hs, C2H,, CH3SSCH3, C,Hlo, C,H,SH, and CH,SH. Acarbon/sulfur mass balance is obtained at all substrate pressures at 25 "C, and at the single substrate pressure examined at 120 "C. In the presence of propylene four additional products, n-C,H,,, CH,S(CH,),CH,, (CH,CH,CH,),S, and CH,=CH-CH2SC2H5, were found. Only a small fraction of photochemically excited methyl ethyl sulfide molecules undergoes chemical decomposition. The two primary processes and subsequent reactions of the radicals so formed account for the observed products. R,,,/R,, has a value of 1.32 at 25 "C.

Reactions of thiyl radicals. XII. Triplet mercury photosensitized decomposition of ethyl sulfide in the gas phase

“…The absorbed light intensity in the actinometry experiments was determined to be 3.6 X ,.teinstein min-1. In previo~~s determinations of the quantum yields in the direct photolysis of methyl sulfide ( I ) and methylethyl sulfide (5). interference filters were-employed to isolate the photolysing wavelengths, 2288 A.…”